New Strategies for Biofilm Related Infections

NCT ID: NCT03784807

Last Updated: 2018-12-24

Basic Information

• Recruitment Status: UNKNOWN
• Total Enrollment: 99 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2018-11-02
• Study Completion Date: 2020-11-30

Brief Summary

This study aims to develop new assays for synovial fluid analysis able to improve diagnosis of prosthetic joint infections. In particular, use of synovial calprotectin as marker of infection, confocal laser scanning microscopy (CLSM) analysis and methods to assess antimicrobial susceptibility will be evaluated in synovial fluids collected from patients with septic and aseptic failure of the prosthetic implant.

Detailed Description

Infection of prosthetic joints is a common complication that may occur any time after implantation. These infections require a prompt and accurate diagnosis to ensure an optimal surgical and medical management of infected patient. Despite acute infections occurring in the first weeks after surgery are easy to diagnose or when they are associated to bacteremia, diagnosis becomes challenging when infection develops for several months before diagnosis or it is caused by low virulent pathogens. Prosthetic joint infections and more widely osteo-articular infections represent the classic biofilm related infections. Biofilm is usually defined as a microbial community enveloped in a self-produced polymeric matrix. Biofilm production allows bacteria to strictly adhere to inert and biotic substrates, evade host defenses and resist to antibiotics by building a physical barrier to penetration of antimicrobials and favoring dissemination of determinants of resistance. Microbiological cultures contribute to diagnosis of infection, providing identification of the pathogen and, most importantly, definition of antibiotic susceptibility. Nonetheless, in about 15-20% of cases, culture fails to growth the pathogen. Diagnosis of prosthetic joint infection may occur either pre- or intra-operatively. In both cases analysis of synovial fluid is crucial, especially when performed before surgery when results from culture, leukocyte esterase, alpha defensin test, leukocyte count and differential may lead to define the most accurate strategy to approach patients with implant failure. However, culture of synovial fluid is characterized by a limited sensitivity in respect, for instance to culture of periprosthetic tissues or implant components. One of the causes of the lower sensitivity of synovial fluid culture might be the presence of the so called "biofilm like aggregates", agglomerates of microorganisms embedded in a matrix which has been hypothesized to act as a protective barrier. Leukocyte esterase test may give false positive results in samples strongly contaminated by blood or with metal on metal reaction, while the high costs for alpha defensin determination markedly limited its use. On the other hand, studies aiming to evaluate other synovial markers of infections like calprotectin are insufficient to support their use in routine diagnosis of prosthetic joint infection.

An alternative approach to diagnosis of these infections could be represented by use of confocal laser scanning microscopy (CLSM) which allows to detect microorganisms in synovial fluid and in tissues. This novel approach could also be used for a "real time" diagnosis during surgery while waiting for culture results.

Another issue in diagnosis of prosthetic joint infections is related to assessment of antimicrobial susceptibility. In fact, it is well known that biofilm embedded bacteria are more resistant to antibiotics than their planktonic counterpart. Since available methods for determination of antibiotic susceptibility are based on planktonic cells, it may be hypothesized that they underestimate the real antimicrobial concentration able to inhibit growth of bacteria embedded in a biofilm as occur during infection. Although several methods have been proposed to evaluate antimicrobial susceptibility pattern of biofilm microorganisms, none of them has been proposed for routinely use. However, in some cases when therapy fails to eradicate infection, evaluation of antibiotic susceptibility of biofilm embedded bacteria could provide important information to optimize antimicrobial therapy.

Therefore, diagnosis of biofilm related infections, particularly prosthetic ones is quite far from being optimized. In this sense, development of a panel able to shorten turn around time of microbiological analyses and to improve patient management could significantly ameliorate approach to patients, limiting worsening in patient's quality of life and reducing costs for health system.

Conditions

Prosthetic Joint Infection

Keywords

synovial fluid analysis

Study Design

• Observational Model Type: CASE_CONTROL
• Study Time Perspective: PROSPECTIVE

Study Groups

Infected

Patients with prosthetic joint or osteoarticular infection

synovial calprotectin, confocal laser microscopy

Intervention Type: DIAGNOSTIC_TEST

Calprotectin will be determined in synovial fluid of patients with septic and aseptic failure of their prosthesis. CLSM will be used to detect presence of microorganisms in synovial fluid. Susceptibility to antimicrobials of bacterial strains isolated from patients with prosthetic joint infections will be assessed using planktonic cells and biofilm associated bacteria

Not infected

Patients with implant failure not due to infection

synovial calprotectin, confocal laser microscopy

Intervention Type: DIAGNOSTIC_TEST

Calprotectin will be determined in synovial fluid of patients with septic and aseptic failure of their prosthesis. CLSM will be used to detect presence of microorganisms in synovial fluid. Susceptibility to antimicrobials of bacterial strains isolated from patients with prosthetic joint infections will be assessed using planktonic cells and biofilm associated bacteria

Interventions

synovial calprotectin, confocal laser microscopy

Calprotectin will be determined in synovial fluid of patients with septic and aseptic failure of their prosthesis. CLSM will be used to detect presence of microorganisms in synovial fluid. Susceptibility to antimicrobials of bacterial strains isolated from patients with prosthetic joint infections will be assessed using planktonic cells and biofilm associated bacteria

Intervention Type: DIAGNOSTIC_TEST

Eligibility Criteria

Inclusion Criteria

• Diagnosis of implant failure or osteoarticular infections
• Collection of a sufficient amount of synovial fluid
• Informed Consent signed

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

I.R.C.C.S Ospedale Galeazzi-Sant'Ambrogio

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Elena De Vecchi, MSc

Role: PRINCIPAL_INVESTIGATOR

IRCCS Istituto Ortopedico Galeazzi

Locations

IRCCS Istituto Ortopedico Galeazzi

Milan, MI, Italy

Site Status: RECRUITING

Countries

Italy

Central Contacts

Elena Cittera, MSc

Role: CONTACT

Phone: 00390266214057

Email: elena.cittera@grupposandonato.it

Elena De Vecchi, MSc

Role: CONTACT

Phone: 00390266214080

Email: elena.devecchi@grupposandonato.it

Facility Contacts

Elena Cittera, MSc

Role: primary

Other Identifiers

Diafilm

Identifier Type: -

Identifier Source: org_study_id